Correlations in polycyclic aromatic hydrocarbon (PAH) concentrations in UK ambient air and implications for source apportionment

The extent of correlation in polycyclic aromatic hydrocarbon (PAH) concentration data obtained by the UK PAH Monitoring and Analysis Air Quality Network from March 2008 to November 2010 has been assessed. Application of principal component analysis (PCA) to the dataset has revealed that the concentrations of the vast majority of PAHs are very highly correlated. The use of diagnostic PAH ratios (including a new benzo[b]naph[2,1-d]thiophene/benzo[a]pyrene diagnostic ratio), and a novel 'combined diagnostic ratio - PCA' approach has revealed information about the main sources of PAH at individual Network sites, allowing the sites to be grouped in terms of those influenced by solid fuel use, industry and traffic, and those of an urban or rural nature. Solid fuel use has also been delineated from other fuel burning. Conclusions are drawn about a number of UK PAH Network sites - four sites are shown to be influenced significantly by solid fuel use, and the sites in South Wales and at London Marylebone Road are found to be located in distinct and unusual PAH pollution climates - the identification of a unique PAH pollution climate in South Wales is a key and novel conclusion of the work.     

Utility of North Atlantic Right Whale Museum Specimens for Assessing Changes in Genetic Diversity

Abstract: We examined six historical specimens of the endangered North Atlantic right whale ( Eubalaena glacialis ) using DNA isolated from documented baleen plates from the late nineteenth and early twentieth centuries. Sequences from the mitochondrial DNA (mtDNA) control region from these samples were compared with those from a near-exhaustive survey (269 of approximately 320 individuals) of the remaining right whales in the western North Atlantic Ocean. Our results suggest that there has been only relatively modest change in maternal lineage diversity over the past century in the North Atlantic right whale population. Any significant reduction in genetic variation in the species most likely occurred prior to the late nineteenth century. One historical specimen was from the last documented female capable of propagating one of the maternal lineages in the population today; no females in the existing population have been found to carry this mtDNA haplotype. Analysis of the only specimens from the eastern North Atlantic right whale population ever to be examined revealed that eastern and western North Atlantic right whales may not have been genetically differentiated populations. Loss of gene diversity experienced by North Atlantic right whales over the last century has been modest, and the six decades of protection have been successful in maintaining much of the maternal lineage diversity that was present in the late nineteenth century.     

Building institutions based on information disclosure: lessons from GRI's sustainability reporting

Global Reporting Initiative (GRI) is the best-known framework for voluntary reporting of environmental and social performance by business worldwide. Using extensive empirical data, including interviews and documentary analysis, we examine GRI's organizational field and conclude that since its modest beginnings in 1999 GRI has been by several measures a successful institutionalization project. But the institutional logic of this new entity, as an instrument for corporate sustainability management, leaves out one of the central elements of the initial vision for GRI: as a mobilizing agent for many societal actors. This emergent logic reflects GRI's dominant constituency – large global companies and financial institutions and international business management consultancies – and not the less active civil society organizations and organized labor. We attribute these developments to factors such as building GRI within the existing institutional structures; the highly inclusive multistakeholder process; and the underdeveloped base of information users. From the institutional theory perspective, this case shows how the process of institutionalization is deeply affected by initial strategies of the founders, and how it reproduces existing power relations. From the governance perspective, this case leads us to question the power of commodified information to mobilize civil society and to strengthen governance based on partnerships.     

Weather-mediated natural selection on arrival time in cliff swallows (Petrochelidon pyrrhonota)

An unusually long period of cold weather in May 1996 caused extensive mortality among insectivorous cliff swallows (Petrochelidon pyrrhonota) in the northern and central Great Plains. We analyzed how viability selection affected spring arrival time in a migratory Nebraska population by comparing capture histories of survivors with those of birds known to have died and by documenting how arrival time changed in the year following the selection event. Surviving birds had significantly later first-capture dates (an index of arrival time) in the years prior to selection than those that died; a significant selection differential suggested directional selection for birds that arrived later. Colony sites were occupied significantly later following the selection event, and the distribution of first-capture dates in the season after selection was significantly shifted toward later arrivals. Offspring of the survivors tended to arrive later than birds of the same age prior to the selection event. While major weather-caused mortality events of this magnitude are rare in the study area, spells of cold weather severe enough to cause limited mortality are frequent in April and early May. At least 25 probable mortality events of varying severity were identified in the last 50 years based on climatological data. Periodic weather-mediated selection against early arrival constrains the cliff swallow’s breeding season and may partly prevent directional selection for earlier nesting. Received: 19 October 1999 / Received in revised form: 15 January 2000 / Accepted: 24 January 2000     

养活九十亿人

本世纪期间，技术进展已经使农作物生产率发生了革命，但农作物产率的提高已经开始放慢，而世界人口却继续增长.土地退化和水资源的压力是对非常需要的土地生产率提高的严重障碍.满足21世纪全球食品需要将要求一致的人口控制政策，推进可持续消费，和大大提高我们对土地、水及其它自然资源的使用效率.本文提供了对这些问题的前瞻性分析和解决这些问题的建议.     

Sensitivity analysis of the asymptotic behavior of a model for the environmental movement of radionuclides

The asymptotic behavior of a linear compartment model for the environmental movement of radionuclides is investigated. Here, the expression asymptotic behavior is used to designate the behavior of q(t) as t → ∞, where q is the solution of a vector differential equation of the form dq/dt = h + Kq. The asymptotic behavior of such equations is described. For the model and conditions under consideration, each element of q converges monotonically to a steady-state value. A hydrologic system is defined and used to illustrate this behavior. An approach to sensitivity analysis employing Latin hypercube sampling, rank transformations and stepwise regression is presented and then applied to this system. A total of 20 independent variables is introduced and the following dependent variables are investigated for the various components of the system: amount of radionuclide present at steady state. concentration of radionuclide at steady state, and time required to reach 90% of steady state. Finally, an application of asymptotic behavior in the analysis of a hypothetical site for the geologic isolation of high-level radioactive waste is described and a brief discussion of differential sensitivity analysis is given.     

Adsorption of As(III) on chitosan-Fe-crosslinked complex (Ch-Fe)

It was reported the adsorption of As(III) on the surface of the chitosan-Fe-crosslinked complex. Theoretical correlation of the experimental equilibrium adsorption data for As(III)/Ch-Fe system is best explained by the non-linearized form Langmuir-Freundlich isotherm model. At optimum conditions, pH 9.0, the maximum adsorption capacity, calculated using the Langmuir-Freundlich isotherm model was 13.4 mg g⁻¹. The adsorption kinetics of As(III) onto Ch-Fe are described by the pseudo-first-order kinetic equation. The results of the Mössbauer spectroscopy showed that there is no redox process on the surface of the adsorbent.     

Exposure to strange adults does not cause pregnancy disruption or infanticide in the gray-tailed vole

A widely accepted paradigm in mammalian behavioral biology is that exposure to unfamiliar males causes pregnancy disruption in female rodents (commonly known as the Bruce effect). This behavioral phenomenon has been demonstrated in the laboratory with at least 12 species of rodents, primarily within the genus Microtus, and is supposedly an adaptation that provides male perpetrators with reproductive access to females, and functions, for females, as a counterstrategy to infanticide. However, neither the Bruce effect nor its adaptive significance have been tested experimentally in the field. In a controlled field study, we exposed reproducing female gray-tailed voles (Microtus canicaudus) to treatments in which males were removed and replaced by either unfamiliar males or females, and found no significant differences in intervals between parturitions, number of pregnancies, and juvenile recruitment among the treatment and control animals. Thus, we conclude that neither the Bruce effect nor infanticide occurred differentially as a consequence of the treatments in gray-tailed voles. Multimale mating to confuse paternity, and postpartum estrus resulting in simultaneous pregnancy and lactation may deter infanticide and functionally negate any benefits of pregnancy disruption in gray-tailed voles and perhaps other murid rodents with similar mating systems. In light of our results, we recommend field verification for other species of murid rodents that exhibit the Bruce effect in the laboratory before the results are applied to evolutionary theory. Received: 12 May 1998 / Accepted after revision: 6 September 1998     

Transaction costs for carbon sequestration projects in the tropical forest sector

There is general consensus that carbon (C) sequestration projects in forests are a relatively low cost option for mitigating climate change, but most studies on the subject have assumed that transaction costs are negligible. The objectives of the study were to examine transaction costs for forest C sequestration projects and to determine the significance of the costs based on economic analyses. Here we examine four case studies of active C sequestration projects being implemented in tropical countries and developed for the C market. The results from the case studies were then used with a dynamic forest and land use economic model to investigate how transaction costs affect the efficiency and cost of forest C projects globally. In the case studies transaction costs ranged from 0.38 to 27 million US dollars ($0.09 to $7.71/t CO₂) or 0.3 to 270 % of anticipated income depending principally on the price of C and project size. The three largest cost categories were insurance (under the voluntary market; 41–89 % of total costs), monitoring (3–42 %) and regulatory approval (8–50 %). The global analysis indicated that most existing estimates of marginal costs of C sequestration are underestimated by up to 30 % because transaction costs were not included.